De Nicola Francesco, Viola Ilenia, Tenuzzo Lorenzo Donato, Rasch Florian, Lohe Martin R, Nia Ali Shaygan, Schütt Fabian, Feng Xinliang, Adelung Rainer, Lupi Stefano
Graphene Labs, Istituto Italiano di Tecnologia, Via Morego 30, 16163, Genova, Italy.
CNR NANOTEC-Institute of Nanotechnology, S.Li.M. Lab, Department of Physics, University of Rome La Sapienza, P.le A. Moro 5, 00185, Roma, Italy.
Sci Rep. 2020 Feb 5;10(1):1916. doi: 10.1038/s41598-020-58860-4.
Graphene hydrophobic coatings paved the way towards a new generation of optoelectronic and fluidic devices. Nevertheless, such hydrophobic thin films rely only on graphene non-polar surface, rather than taking advantage of its surface roughness. Furthermore, graphene is typically not self-standing. Differently, carbon aerogels have high porosity, large effective surface area due to their surface roughness, and very low mass density, which make them a promising candidate as a super-hydrophobic material for novel technological applications. However, despite a few works reporting the general super-hydrophobic and lipophilic behavior of the carbon aerogels, a detailed characterization of their wetting properties is still missing, to date. Here, the wetting properties of graphene aerogels are demonstrated in detail. Without any chemical functionalization or patterning of their surface, the samples exhibit a super-lipophilic state and a stationary super-hydrophobic state with a contact angle up to 150 ± 15° and low contact angle hysteresis ≈ 15°, owing to the fakir effect. In addition, the adhesion force of the graphene aerogels in contact with the water droplets and their surface tension are evaluated. For instance, the unique wettability and enhanced liquid absorption of the graphene aerogels can be exploited for reducing contamination from oil spills and chemical leakage accidents.
石墨烯疏水涂层为新一代光电器件和流体设备铺平了道路。然而，此类疏水薄膜仅依赖于石墨烯的非极性表面，而非利用其表面粗糙度。此外，石墨烯通常无法自立。与之不同的是，碳气凝胶具有高孔隙率、因其表面粗糙度而具有较大的有效表面积以及极低的质量密度，这使其成为新型技术应用中超级疏水材料的一个有前景的候选者。然而，尽管有一些研究报告了碳气凝胶的一般超疏水和亲油行为，但迄今为止，对其润湿性的详细表征仍然缺失。在此，详细展示了石墨烯气凝胶的润湿性。在其表面未进行任何化学功能化或图案化处理的情况下，由于法基尔效应，样品呈现出超亲油状态和静态超疏水状态，接触角高达150±15°，接触角滞后约为15°。此外，还评估了石墨烯气凝胶与水滴接触时的粘附力及其表面张力。例如，石墨烯气凝胶独特的润湿性和增强的液体吸收能力可用于减少石油泄漏和化学泄漏事故造成的污染。
